Internal combustion engine control systems are typically steady-state, throttle-based control systems. In a steady-state control system, the torque output of the engine is related to a throttle set point. A driver adjusts a position of an accelerator pedal, which changes the throttle set point. The throttle set point controls the amount of airflow into an intake manifold and cylinders. In other words, the torque output of the engine is related to cylinder airflow, which is based on the throttle set point. After a throttle adjustment, the engine torque eventually settles at a desired value that is related to the cylinder airflow.
Steady-state, engine torque control systems typically determine the throttle set point based on intermediate parameters such as mass air flow rates and manifold absolute pressure. The use of these parameters requires additional computation. Determining the throttle set point based on intermediate parameters also involves numerous diagnostic requirements. As a result, these systems are overly complex.